Hello Swoop,
Thank you for your reply!
It actually turns out to be the pressure relief valve at the bulkhead filter.
Since this never happened before but now after I switched to a new full tank, I'm thinking either the tank's pressure is too high or since the forklift was sitting outside in the 95 + deg. weather the tank might have just been overpressured?
I will look for a replacement valve online and see if the current one is just faulty.
Thomas